Vaishnavi Mishra

Developed a proactive security layer for autonomous AI agents that verifies user-authorized payment intent before transactions are processed. Implemented Ed25519 cryptographic signatures, a two-tier firewall with rule-based validation and risk scoring, prompt injection detection, lookalike merchant identification, and an emergency kill switch. Integrated a tamper-evident SHA-256 hash-chained audit trail and a mock UPI sandbox to demonstrate secure payment authorization.

• Cryptographic verification of payment limits, expiry, and authorized payees.
• Risk-based transaction approval, user confirmation, or rejection.
• Automated demo scenarios for payment approval, injection attacks, and emergency revocation.

Built a decentralized freelance marketplace on Base Sepolia featuring smart contract-based USDC escrow, wallet-based authentication, and multisignature dispute resolution. Developed a React Native Android application integrated with a Node.js backend, PostgreSQL database, and Solidity smart contracts to support a secure and transparent freelance workflow.

• Smart contract escrow for managing freelance payments.
• 2-of-3 multisignature arbitration for dispute resolution.
• Sign-In with Ethereum (SIWE) for wallet-based authentication.
• Monorepo architecture with shared types and automated smart contract tests.

Developed a full-stack monitoring dashboard to track microservice health, uptime, latency, and service availability in real time. Built a FastAPI backend with scheduled health checks, persistent metric storage, and WebSocket-based updates, alongside a React dashboard for service management and latency visualization.

• Service registry with configurable health endpoints and monitoring intervals.
• Automated background polling and real-time status updates without page refreshes.
• Latency analytics and health status tracking for identifying service degradation.
• Extensible alerting architecture for downtime, latency spikes, and error rates.